/*!
 * iScroll Lite base on iScroll v4.1.6 ~ Copyright (c) 2011 Matteo Spinelli, http://cubiq.org
 * Released under MIT license, http://cubiq.org/license
 */

(function(){
    var m = Math,
    mround = function (r) {
        return r >> 0;
    },
    vendor = (/webkit/i).test(navigator.appVersion) ? 'webkit' :
    (/firefox/i).test(navigator.userAgent) ? 'Moz' :
    'opera' in window ? 'O' : '',

    // Browser capabilities
    isAndroid = (/android/gi).test(navigator.appVersion),
    isIDevice = (/iphone|ipad/gi).test(navigator.appVersion),
    isPlaybook = (/playbook/gi).test(navigator.appVersion),
    isTouchPad = (/hp-tablet/gi).test(navigator.appVersion),

    has3d = 'WebKitCSSMatrix' in window && 'm11' in new WebKitCSSMatrix(),
    hasTouch = 'ontouchstart' in window && !isTouchPad,
    hasTransform = vendor + 'Transform' in document.documentElement.style,
    hasTransitionEnd = isIDevice || isPlaybook,

    nextFrame = (function() {
        return window.requestAnimationFrame
        || window.webkitRequestAnimationFrame
        || window.mozRequestAnimationFrame
        || window.oRequestAnimationFrame
        || window.msRequestAnimationFrame
        || function(callback) {
            return setTimeout(callback, 17);
        }
    })(),
    cancelFrame = (function () {
        return window.cancelRequestAnimationFrame
        || window.webkitCancelRequestAnimationFrame
        || window.mozCancelRequestAnimationFrame
        || window.oCancelRequestAnimationFrame
        || window.msCancelRequestAnimationFrame
        || clearTimeout
    })(),

    // Events
    RESIZE_EV = 'onorientationchange' in window ? 'orientationchange' : 'resize',
    START_EV = hasTouch ? 'touchstart' : 'mousedown',
    MOVE_EV = hasTouch ? 'touchmove' : 'mousemove',
    END_EV = hasTouch ? 'touchend' : 'mouseup',
    CANCEL_EV = hasTouch ? 'touchcancel' : 'mouseup',

    // Helpers
    trnOpen = 'translate' + (has3d ? '3d(' : '('),
    trnClose = has3d ? ',0)' : ')',

    // Constructor
    iScroll = function (el, options) {
        var that = this,
        doc = document,
        i;

        that.wrapper = typeof el == 'object' ? el : doc.getElementById(el);
        that.wrapper.style.overflow = 'hidden';
        that.scroller = that.wrapper.children[0];

        // Default options
        that.options = {
            hScroll: true,
            vScroll: true,
            x: 0,
            y: 0,
            bounce: true,
            bounceLock: false,
            momentum: true,
            lockDirection: true,
            useTransform: true,
            useTransition: false,

            // Events
            onRefresh: null,
            onBeforeScrollStart: function (e) {
                e.preventDefault();
            },
            onScrollStart: null,
            onBeforeScrollMove: null,
            onScrollMove: null,
            onBeforeScrollEnd: null,
            onScrollEnd: null,
            onTouchEnd: null,
            onDestroy: null
        };

        // User defined options
        for (i in options) that.options[i] = options[i];

        // Set starting position
        that.x = that.options.x;
        that.y = that.options.y;

        // Normalize options
        that.options.useTransform = hasTransform ? that.options.useTransform : false;
        that.options.hScrollbar = that.options.hScroll && that.options.hScrollbar;
        that.options.vScrollbar = that.options.vScroll && that.options.vScrollbar;
        that.options.useTransition = hasTransitionEnd && that.options.useTransition;

        // Set some default styles
        that.scroller.style[vendor + 'TransitionProperty'] = that.options.useTransform ? '-' + vendor.toLowerCase() + '-transform' : 'top left';
        that.scroller.style[vendor + 'TransitionDuration'] = '0';
        that.scroller.style[vendor + 'TransformOrigin'] = '0 0';
        if (that.options.useTransition) that.scroller.style[vendor + 'TransitionTimingFunction'] = 'cubic-bezier(0.33,0.66,0.66,1)';
        if (that.options.useTransform) that.scroller.style[vendor + 'Transform'] = trnOpen + that.x + 'px,' + that.y + 'px' + trnClose;
        else that.scroller.style.cssText += ';position:absolute;top:' + that.y + 'px;left:' + that.x + 'px';
        that.refresh();

        that._bind(RESIZE_EV, window);
        that._bind(START_EV);
        if (!hasTouch) that._bind('mouseout', that.wrapper);
    };

    // Prototype
    iScroll.prototype = {
        enabled: true,
        x: 0,
        y: 0,
        steps: [],
        scale: 1,
	
        handleEvent: function (e) {
            var that = this;
            switch(e.type) {
                case START_EV:
                    if (!hasTouch && e.button !== 0) return;
                    that._start(e);
                    break;
                case MOVE_EV:
                    that._move(e);
                    break;
                case END_EV:
                case CANCEL_EV:
                    that._end(e);
                    break;
                case RESIZE_EV:
                    that._resize();
                    break;
                case 'mouseout':
                    that._mouseout(e);
                    break;
                case 'webkitTransitionEnd':
                    that._transitionEnd(e);
                    break;
            }
        },

        _resize: function () {
            this.refresh();
        },
        
        _pos: function (x, y) {
            x = this.hScroll ? x : 0;
            y = this.vScroll ? y : 0;

            if (this.options.useTransform) {
                this.scroller.style[vendor + 'Transform'] = trnOpen + x + 'px,' + y + 'px' + trnClose + ' scale(' + this.scale + ')';
            } else {
                x = mround(x);
                y = mround(y);
                this.scroller.style.left = x + 'px';
                this.scroller.style.top = y + 'px';
            }

            this.x = x;
            this.y = y;
        },

        _start: function (e) {
            var that = this,
            point = hasTouch ? e.touches[0] : e,
            matrix, x, y;
            if (!that.enabled) return;

            if (that.options.onBeforeScrollStart) that.options.onBeforeScrollStart.call(that, e);
            if (that.options.useTransition) that._transitionTime(0);

            that.moved = false;
            that.animating = false;
            that.zoomed = false;
            that.distX = 0;
            that.distY = 0;
            that.absDistX = 0;
            that.absDistY = 0;
            that.dirX = 0;
            that.dirY = 0;

            if (that.options.momentum) {
                if (that.options.useTransform) {
                    // Very lame general purpose alternative to CSSMatrix
                    matrix = getComputedStyle(that.scroller, null)[vendor + 'Transform'].replace(/[^0-9-.,]/g, '').split(',');
                    x = matrix[4] * 1;
                    y = matrix[5] * 1;
                } else {
                    x = getComputedStyle(that.scroller, null).left.replace(/[^0-9-]/g, '') * 1;
                    y = getComputedStyle(that.scroller, null).top.replace(/[^0-9-]/g, '') * 1;
                }
			
                if (x != that.x || y != that.y) {
                    if (that.options.useTransition) that._unbind('webkitTransitionEnd');
                    else cancelFrame(that.aniTime);
                    that.steps = [];
                    that._pos(x, y);
                }
                //ANOTHER KUKU HACK! IE
                if(that.options.vertical) {
                    that.vertical();
                }
            }
            that.startX = that.x;
            that.startY = that.y;
            that.pointX = point.pageX;
            that.pointY = point.pageY;

            that.startTime = e.timeStamp || Date.now();

            if (that.options.onScrollStart) that.options.onScrollStart.call(that, e);

            that._bind(MOVE_EV);
            that._bind(END_EV);
            that._bind(CANCEL_EV);
        },
	
        _move: function (e) {
            var that = this,
            point = hasTouch ? e.touches[0] : e,
            deltaX = point.pageX - that.pointX,
            deltaY = point.pageY - that.pointY,
            newX = that.x + deltaX,
            newY = that.y + deltaY,
            timestamp = e.timeStamp || Date.now();

            if (that.options.onBeforeScrollMove) that.options.onBeforeScrollMove.call(that, e);

            that.pointX = point.pageX;
            that.pointY = point.pageY;

            // Slow down if outside of the boundaries
            if (newX > 0 || newX < that.maxScrollX) {
                newX = that.options.bounce ? that.x + (deltaX / 2) : newX >= 0 || that.maxScrollX >= 0 ? 0 : that.maxScrollX;
            }
            if (newY > 0 || newY < that.maxScrollY) { 
                newY = that.options.bounce ? that.y + (deltaY / 2) : newY >= 0 || that.maxScrollY >= 0 ? 0 : that.maxScrollY;
            }

            if (that.absDistX < 6 && that.absDistY < 6) {
                that.distX += deltaX;
                that.distY += deltaY;
                that.absDistX = m.abs(that.distX);
                that.absDistY = m.abs(that.distY);

                return;
            }

            // Lock direction
            if (that.options.lockDirection) {
                if (that.absDistX > that.absDistY + 5) {
                    newY = that.y;
                    deltaY = 0;
                } else if (that.absDistY > that.absDistX + 5) {
                    newX = that.x;
                    deltaX = 0;
                }
            }

            that.moved = true;
            that._pos(newX, newY);
            that.dirX = deltaX > 0 ? -1 : deltaX < 0 ? 1 : 0;
            that.dirY = deltaY > 0 ? -1 : deltaY < 0 ? 1 : 0;

            if (timestamp - that.startTime > 300) {
                that.startTime = timestamp;
                that.startX = that.x;
                that.startY = that.y;
            }
		
            if (that.options.onScrollMove) that.options.onScrollMove.call(that, e);
        },
	
        _end: function (e) {
            if (hasTouch && e.touches.length != 0) return;

            var that = this,
            point = hasTouch ? e.changedTouches[0] : e,
            target, ev,
            momentumX = {
                dist:0, 
                time:0
            },
            momentumY = {
                dist:0, 
                time:0
            },
            duration = (e.timeStamp || Date.now()) - that.startTime,
            newPosX = that.x,
            newPosY = that.y,
            newDuration;

            that._unbind(MOVE_EV);
            that._unbind(END_EV);
            that._unbind(CANCEL_EV);

            if (that.options.onBeforeScrollEnd) that.options.onBeforeScrollEnd.call(that, e);

            if (!that.moved) {
                if (hasTouch) {
                    // Find the last touched element
                    target = point.target;
                    while (target.nodeType != 1) target = target.parentNode;

                    if (target.tagName != 'SELECT' && target.tagName != 'INPUT' && target.tagName != 'TEXTAREA') {
                        ev = document.createEvent('MouseEvents');
                        ev.initMouseEvent('click', true, true, e.view, 1,
                            point.screenX, point.screenY, point.clientX, point.clientY,
                            e.ctrlKey, e.altKey, e.shiftKey, e.metaKey,
                            0, null);
                        ev._fake = true;
                        target.dispatchEvent(ev);
                    }
                }

                that._resetPos(200);

                if (that.options.onTouchEnd) that.options.onTouchEnd.call(that, e);
                return;
            }

            if (duration < 300 && that.options.momentum) {
                momentumX = newPosX ? that._momentum(newPosX - that.startX, duration, -that.x, that.scrollerW - that.wrapperW + that.x, that.options.bounce ? that.wrapperW : 0) : momentumX;
                momentumY = newPosY ? that._momentum(newPosY - that.startY, duration, -that.y, (that.maxScrollY < 0 ? that.scrollerH - that.wrapperH + that.y : 0), that.options.bounce ? that.wrapperH : 0) : momentumY;

                newPosX = that.x + momentumX.dist;
                newPosY = that.y + momentumY.dist;

                if ((that.x > 0 && newPosX > 0) || (that.x < that.maxScrollX && newPosX < that.maxScrollX)) momentumX = {
                    dist:0, 
                    time:0
                };
                if ((that.y > 0 && newPosY > 0) || (that.y < that.maxScrollY && newPosY < that.maxScrollY)) momentumY = {
                    dist:0, 
                    time:0
                };
            }

            if (momentumX.dist || momentumY.dist) {
                newDuration = m.max(m.max(momentumX.time, momentumY.time), 10);

                that.scrollTo(mround(newPosX), mround(newPosY), newDuration);

                if (that.options.onTouchEnd) that.options.onTouchEnd.call(that, e);
                return;
            }

            that._resetPos(200);
            if (that.options.onTouchEnd) that.options.onTouchEnd.call(that, e);
        },
	
        _resetPos: function (time) {
            var that = this,
            resetX = that.x >= 0 ? 0 : that.x < that.maxScrollX ? that.maxScrollX : that.x,
            resetY = that.y >= 0 || that.maxScrollY > 0 ? 0 : that.y < that.maxScrollY ? that.maxScrollY : that.y;

            if (resetX == that.x && resetY == that.y) {
                if (that.moved) {
                    if (that.options.onScrollEnd) that.options.onScrollEnd.call(that);		// Execute custom code on scroll end
                    that.moved = false;
                }

                return;
            }

            that.scrollTo(resetX, resetY, time || 0);
        },
	
        _mouseout: function (e) {
            var t = e.relatedTarget;

            if (!t) {
                this._end(e);
                return;
            }

            while (t = t.parentNode) if (t == this.wrapper) return;
		
            this._end(e);
        },

        _transitionEnd: function (e) {
            var that = this;

            if (e.target != that.scroller) return;

            that._unbind('webkitTransitionEnd');
		
            that._startAni();
        },

        /**
	 *
	 * Utilities
	 *
	 */
        _startAni: function () {
            var that = this,
            startX = that.x, startY = that.y,
            startTime = Date.now(),
            step, easeOut,
            animate;

            if (that.animating) return;

            if (!that.steps.length) {
                that._resetPos(400);
                return;
            }

            step = that.steps.shift();

            if (step.x == startX && step.y == startY) step.time = 0;

            that.animating = true;
            that.moved = true;

            if (that.options.useTransition) {
                that._transitionTime(step.time);
                that._pos(step.x, step.y);
                that.animating = false;
                if (step.time) that._bind('webkitTransitionEnd');
                else that._resetPos(0);
                return;
            }
		
            animate = function () {
                var now = Date.now(),
                newX, newY;

                if (now >= startTime + step.time) {
                    that._pos(step.x, step.y);
                    that.animating = false;
                    if (that.options.onAnimationEnd) that.options.onAnimationEnd.call(that);			// Execute custom code on animation end
                    that._startAni();
                    return;
                }

                now = (now - startTime) / step.time - 1;
                easeOut = m.sqrt(1 - now * now);
                newX = (step.x - startX) * easeOut + startX;
                newY = (step.y - startY) * easeOut + startY;
                that._pos(newX, newY);
                if (that.animating) that.aniTime = nextFrame(animate);
            };
		
            animate();
        },

        _transitionTime: function (time) {
            this.scroller.style[vendor + 'TransitionDuration'] = time + 'ms';
        },
	
        _momentum: function (dist, time, maxDistUpper, maxDistLower, size) {
            var deceleration = 0.0006,
            speed = m.abs(dist) / time,
            newDist = (speed * speed) / (2 * deceleration),
            newTime = 0, outsideDist = 0;

            // Proportinally reduce speed if we are outside of the boundaries 
            if (dist > 0 && newDist > maxDistUpper) {
                outsideDist = size / (6 / (newDist / speed * deceleration));
                maxDistUpper = maxDistUpper + outsideDist;
                speed = speed * maxDistUpper / newDist;
                newDist = maxDistUpper;
            } else if (dist < 0 && newDist > maxDistLower) {
                outsideDist = size / (6 / (newDist / speed * deceleration));
                maxDistLower = maxDistLower + outsideDist;
                speed = speed * maxDistLower / newDist;
                newDist = maxDistLower;
            }

            newDist = newDist * (dist < 0 ? -1 : 1);
            newTime = speed / deceleration;

            return {
                dist: newDist, 
                time: mround(newTime)
            };
        },

        _offset: function (el) {
            var left = -el.offsetLeft,
            top = -el.offsetTop;
			
            while (el = el.offsetParent) {
                left -= el.offsetLeft;
                top -= el.offsetTop;
            } 

            return {
                left: left, 
                top: top
            };
        },

        _bind: function (type, el, bubble) {
            (el || this.scroller).addEventListener(type, this, !!bubble);
        },

        _unbind: function (type, el, bubble) {
            (el || this.scroller).removeEventListener(type, this, !!bubble);
        },


        /**
	 *
	 * Public methods
	 *
	 */
        destroy: function () {
            var that = this;

            that.scroller.style[vendor + 'Transform'] = '';

            // Remove the event listeners
            that._unbind(RESIZE_EV, window);
            that._unbind(START_EV);
            that._unbind(MOVE_EV);
            that._unbind(END_EV);
            that._unbind(CANCEL_EV);
            that._unbind('mouseout', that.wrapper);
            if (that.options.useTransition) that._unbind('webkitTransitionEnd');
		
            if (that.options.onDestroy) that.options.onDestroy.call(that);
        },
        
        refresh: function () {
            var that = this,
            offset;
            // KUKU HACK! FOR IE - using jQuery!
            try {
                that.wrapperW = $(that.wrapper).width();
            } catch(err) {
                that.wrapperW = that.wrapper.clientWidth;
            }
            that.wrapperH = that.wrapper.clientHeight;

            that.scrollerW = that.scroller.offsetWidth;
            that.scrollerH = that.scroller.offsetHeight;
            that.maxScrollX = that.wrapperW - that.scrollerW;
            that.maxScrollY = that.wrapperH - that.scrollerH;
            that.dirX = 0;
            that.dirY = 0;

            that.hScroll = that.options.hScroll && that.maxScrollX < 0;
            that.vScroll = that.options.vScroll && (!that.options.bounceLock && !that.hScroll || that.scrollerH > that.wrapperH);

            offset = that._offset(that.wrapper);
            that.wrapperOffsetLeft = -offset.left;
            that.wrapperOffsetTop = -offset.top;


            that.scroller.style[vendor + 'TransitionDuration'] = '0';

            that._resetPos(200);
        },

        scrollTo: function (x, y, time, relative) {
            var that = this,
            step = x,
            i, l;

            that.stop();

            if (!step.length) step = [{
                x: x, 
                y: y, 
                time: time, 
                relative: relative
            }];
		
            for (i=0, l=step.length; i<l; i++) {
                if (step[i].relative) {
                    step[i].x = that.x - step[i].x;
                    step[i].y = that.y - step[i].y;
                }
                that.steps.push({
                    x: step[i].x, 
                    y: step[i].y, 
                    time: step[i].time || 0
                });
            }

            that._startAni();
        },

        scrollToElement: function (el, time) {
            var that = this, pos;
            el = el.nodeType ? el : that.scroller.querySelector(el);
            if (!el) return;

            pos = that._offset(el);
            pos.left += that.wrapperOffsetLeft;
            pos.top += that.wrapperOffsetTop;

            pos.left = pos.left > 0 ? 0 : pos.left < that.maxScrollX ? that.maxScrollX : pos.left;
            pos.top = pos.top > 0 ? 0 : pos.top < that.maxScrollY ? that.maxScrollY : pos.top;
            time = time === undefined ? m.max(m.abs(pos.left)*2, m.abs(pos.top)*2) : time;

            that.scrollTo(pos.left, pos.top, time);
        },

        disable: function () {
            this.stop();
            this._resetPos(0);
            this.enabled = false;

            // If disabled after touchstart we make sure that there are no left over events
            this._unbind(MOVE_EV);
            this._unbind(END_EV);
            this._unbind(CANCEL_EV);
        },
	
        enable: function () {
            this.enabled = true;
        },
	
        stop: function () {
            cancelFrame(this.aniTime);
            this.steps = [];
            this.moved = false;
            this.animating = false;
        }
    };

    if (typeof exports !== 'undefined') exports.iScroll = iScroll;
    else window.iScroll = iScroll;

})();
